Increase delay and load over time in jMeter - testing

Question

I'm trying to get an increase in delay/pause and load over time in jmeter load testing while keeping the sequence constant. For example -
Initially - 10 samples (of 2 get requests - a,b,a,b,a,b...)
Then after 10 samples, a delay/pause of 10 secs and then 20 samples (a,b,a,b,a,b...)
After the 20 samples, another delay/pause of 20 secs; then 30 samples (a,b,a,b,a,b...)
And so on.
Constraints here being -
Getting exact number of samples
Getting the desired delay
The order of requests should be maintained
The critical section controller helps with maintaining the order of threads but only in a normal thread group. So if I try the ultimate thread group to get the desired variable delay and load, the order and number of samples go haywire.
I've tried the following-
Run test group consecutively
Flow control action
Throughput controller
Module controller
Interleave controller
Synchronizing timer (with and without flow control)
Add think times to children
Is there any way to get this output in jMeter? Or should I just opt for scripting?

Answer 1

Add User Defined Variables and set the following variables there:
samples=10
delay=10
Add Thread Group and specify the required number of threads and iterations
Add Loop Controller under the Thread Group and set "Loop Count" to ${samples}. Put your requests under the Loop Controller
Add JSR223 Sampler and put the following code into Script area:
def delay = vars.get('delay') as long
sleep(delay * 1000)
def new_delay = delay + 10
vars.put('delay', new_delay as String)
def samples = vars.get('samples') as int
def new_samples = samples + 10
vars.put('samples', new_samples as String)